Tjameson suggests that since Chrome can copy the passwords they are not safe. This isn't necessarily so. The passwords are encrypted using the master password.

%APPDATA%MozillaFirefoxProfiles Click the Finder icon in the dock. On the menu bar, click the Go menu, hold down the option or alt key and select Library. A window will open containing your Library folder. Open the Application Support folder, then open the Firefox folder, and then the Profiles folder.

Chrome can copy the files containing the encrypted password, and it can decrypt them if it has the master password. It knows how to decrypt them because the method of encryption is public. It's the key (the master password) that keeps things safe.

RestoreFirefox Restore Password

So the reason Chrome was able to decrypt the file was that the user supplied the master password.–Apr 6 '11 at 1:31. Click death gym.